Infrared Spectrum of Crystalline CH2Cl2and CD2Cl2. Polarization Measurements and Crystal Structure

摘要

The infrared spectra of crystalline CH2Cl2and CD2Cl2were measured at temperatures ranging from 5 to 125deg;K and at 85deg;K, respectively, between 5000 and 200 cmminus;1. Splitting into two or more components was observed for several fundamentals. The mixed-crystal technique was used to prove the origin of the observed splittings, and the isotopic shifts for37Cl and13C as well as the factor-group splittings were identified. These data, together with polarization measurements on polycrystalline-oriented films, relative intensity measurements, and other independent data, such as crystal density and Raman spectrum, were used to determine the crystal structure. The data accumulated are consistent with an orthormbicD2h14(Pbcn)unit cell with four molecules located onC2sites.